Often, printed images strive to reproduce the appearance of actual objects, such as, for example an automobile. An aspect of this reproduction is the replication of the object's colors. One known technique of printing and reproducing the color of an object is to employ a color-ink-jet printer which prints a series of side-by-side colored dots which appear to blend together when viewed at an appropriate distance, thereby simulating the desired color. However, one of the problems with this method of color printing, is that when a person views the image while in close proximity to it, the dot patterns are readily discernible causing the image to lack the crispness of line of the original object.
In an attempt to address this problem, thermal printers have been used to produce solid, continuous colors thereby eliminating the aforementioned problems associated with ink-jet printing. In a typical thermal printing process, donor or thermal transfer foils that consist of a thin material carrying a layer of pigment dispersed in a wax or wax-resin vehicle are used as the printing medium. The thermal transfer foils are loaded into the thermal printer which acts to transfer the pigment onto a receiving surface by applying heat and pressure to selected areas of the foil. While this produced a solid continuous layer of color, the user was limited to the number of available individual foil colors. Accordingly, it was often difficult to obtain a close match to the actual color of the object on the image being printed. In an effort to expand the range of colors printable using thermal transfer foils, a process known as thermal overprinting was employed wherein layers of pigment are transferred form the thermal transfer foils, one-on-top-of-the-other, onto a thermally printable receiving surface. This created a greatly expanded palette of available colors and shades.
However, the above-described overprinting process while significantly increasing the number of available colors, created other problems for the user of the thermal transfer foils. First, each overprinted color had a specific formula associated with it, that is, a certain number of thermal transfer foils were used to apply layers of pigment in a specific order. Therefore, the user not only had to match the color, he/she also had to know the formula or the specific print order of the foils for producing that color and have the appropriate thermal transfer foils on-hand. Moreover, the overprinting process can produce a large number of resulting variations in the shades of colors which made it difficult to arrive at the color or shade most closely approximating that of the object whose image was to be reproduced.
Based on the foregoing, it is the general object of the present invention to provide a method whereby the closest color matches to an object's color, and the corresponding formulas for the color matches can be readily determined by the user.
It is a more specific object of the present invention to provide a method whereby the aforementioned closest matches are derived from the inventory of thermal transfer foils on-hand at a user's facility.